The fuel cell system is a power generating system in which a fuel cell (fuel-cell stack) electrochemically generates electric power by use of fuel gas supplied from a fuel-gas source and oxidant gas supplied from an oxidant-gas source. Usually, air is used as the oxidant gas, and pumped by a compressor to the fuel cell.
According to Patent Literature 1, a controller calculates the target rotational speed of the compressor pumping the air to the fuel cell, on the basis of the accelerator position, the vehicle speed, and the air flow rate in a fuel-cell car, and controls the rotational speed of the compressor and the flow rate of the air fed to the fuel cell. For example, when the value of the flow rate detected by a flow-rate sensor is within a normal range calculated on the basis of the operational condition of the fuel cell, the air flow rate is feedback controlled by use of the detected value of the flow rate. When the detected value of the flow rate deviates from the normal range, the air flow rate (the rotational speed of the compressor) is feedforward controlled.